Hamoodi, from the central Missouri town of Columbia, pleaded guilty last year to violating sanctions against his home country by illegally sending $270,000 to Iraq by way of Jordan for nine years preceding the U.S. invasion of Iraq and the downfall of Saddam Hussein. He was sentenced to three years in prison.
The nuclear-engineer-turned-grocery-store-owner said he sent the money to support educational efforts and to provide much-needed food and healthcare.
The judge who sentenced Hamoodi said while he had good intentions, he had no way of knowing where the money really went. The money, said U.S. District Judge Nanette K. Laughey, was "like feathers being blown in the wind."
Supporters want his sentence commuted to time served, saying he is an innocent victim of a period of political hysteria and religious discrimination.
The Rev. Maureen Dickmann, a former prosecutor who is now a pastor in Columbia, believes federal investigators made too much of the case against Hamoodi.
"They got in so deep they had to do something," she said. "They raided his house and made a big to-do about it. I think they were afraid of getting egg on their face or looking bad."
An editorial in the Columbia Daily Tribune urged readers to sign a petition calling for Hamoodi's release, noting the sanctions are no longer in place.
What President Obama plans to do with the McCaskill petition isn't known, and McCaskill's office hasn't said if she is pushing for Hamoodi's release.